Malicious PDF — malware analysis report

Static analysis result for SHA-256 aa18bd6650c84894…

MALICIOUS

PDF

68.6 KB Created: 2021-10-01 10:56:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: bcdeb944cf707e0b11fd4711d4cb3757 SHA-1: 5816868a3e33f46a8fc09cffa24b2c4fd76874df SHA-256: aa18bd6650c84894a332282f3a5a988ffdc6c3af21fbf945923e4630ab5d789b
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm with numerous external URIs, many pointing to disposable or unknown hosts. The presence of 'cmd' tokens in the document text suggests an attempt to execute commands, likely to facilitate the redirection to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • LOLBin token sequence in document text high SE_LOLBIN_RUN_COMMAND
    Extracted document text contains a Windows script/execution tool name (PowerShell, mshta, cmd, rundll32, regsvr32, …) within 220 characters of a dangerous flag, command verb, or URL. This is a visible 'run this' instruction in HTML/PDF/RTF lure bodies, or — in macro-laden Office files — the macro's own string-pool entries appearing adjacent in extracted text.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://praktijk.zorglink.nl/ckfinder/userfiles/files/kaxevedowejosozeramuzisug.pdf In PDF document text
    • https://lesartsdansmonjardin.com/userfiles/file/20211001055352.pdfIn PDF document text
    • http://kisito.com/userfiles/file/zomivofuxolugusiteluxaf.pdfIn PDF document text
    • http://bacviettech.vn/userfiles/file/nibojaxupaziguwokapog.pdfIn PDF document text
    • http://mishelik.ru/userfiles/file/xijafetifu.pdfIn PDF document text
    • http://hoadon-dientu.net/images/files/rozokurufofuledixen.pdfIn PDF document text
    • http://susutour.com/userfile/file/73004885283.pdfIn PDF document text
    • http://godsownproperties.com/userfiles/file/71903062819.pdfIn PDF document text
    • https://santa.sg/images/users/00000000/files/88307011311.pdfIn PDF document text
    • https://eliteswimmingpoolsinc.com/wp-content/plugins/super-forms/uploads/php/files/16v423e4jejuf3mdcmdt4jhdv3/wakaloze.pdfIn PDF document text
    • http://loaamtran.com/files/usersfiles/files/kezesumevutofufuxabig.pdfIn PDF document text
    • https://imaggu.com/ci/userfiles/files/fonadisukegazak.pdfIn macro / runtime command snippet
    • https://stef-nancy.fr/upload/document/75511284957.pdfIn macro / runtime command snippet
    • http://alrabbanoilandgas.com/file/files/69139352423.pdfIn PDF document text
    • https://ostrichtours.com/ckfinder/userfiles/files/47398976251.pdfIn PDF document text
    • http://marymo.ru/uploads/files/lilaxo.pdfIn PDF document text
    • https://hoovermaids.com/wp-content/plugins/super-forms/uploads/php/files/da6c9645e32b85b63a19081164f7c223/vofifumusavegax.pdfIn PDF document text
    • https://next-engineering.com/userfiles/files/60909760487.pdfIn PDF document text
    • http://semut73.com/contents/files/naxuteram.pdfIn PDF document text
    • http://jvcc.cn/ckfinder/userfiles/files/210911160904834708gll5k.pdfIn PDF document text
    • https://netcsemege.elelmiszer-hazhozszallitas.hu/ckfinder/userfiles/files/difazazudavuxu.pdfIn PDF document text
    • http://riviera.az/userfiles/file/1281789669.pdfIn PDF document text
    • https://birudongker.com/contents/files/28841890945.pdfIn PDF document text
    • https://llibreriaha.com/img/events/file/balujitimoxararefef.pdfIn PDF document text
    • http://loaamtran.com/files/usersfileIn macro / runtime command snippet
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=nerf+pranks+apk+modPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000aeea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAEEA 15248 bytes
SHA-256: 6373db89363acea8400c7fa817f9efadf47efd50878f23ba26655bcef358186c
font_01_sfnt_off0000d533.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD533 10492 bytes
SHA-256: 29974969bcb322d9875fcea31dc4d0935f7d0d2a24690c3175e0840ee9225c57
font_02_sfnt_off0000ed0c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED0C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1